1. Field of the Invention
This invention relates to improvements in a parapet portion of a curtain wall, and more particularly to an improved structure of a parapet portion of a curtain wall which is free from deterioration of the heat-insulating property caused by heat transfer through the parapet portion to and from the external atmosphere, and which is easily constructible.
2. Description of the Prior Art
A curtain wall formed on the outdoor side of a building body by disposing a plurality of panel units as successively arrayed in the vertical and horizontal directions, has been heretofore known and has been widely used. A parapet portion of the curtain wall is constructed by mounting a coping so as to bridge the top of the curtain wall and the top edge portion of the building body. In the prior art structure, if the curtain wall is so constructed as to have the heat-insulating property, the heat-insulating function can be ensured in the curtain wall portion. However, in the parapet portion, heat transfer would occur between the coping and the indoor side of the curtain wall, and hence heat received by the coping from the external atmosphere would be transmitted to the indoor side of the curtain wall, or heat stored in a room would be transmitted from the indoor side of the curtain wall to the coping and would be eventually radiated to the external atmosphere. Accordingly, the structure of the parapet portion in the prior art had the shortcomings that even if a heat-insulating curtain wall is employed, the heat-insulating property would be deteriorated, and that in the case where the temperature of the external atmosphere is low, damp enclosed between the curtain wall and the building body would reach the inner surface of the coping and would dew the inner surface.
Also, the parapet portion of the curtain wall in the prior art had the shortcoming that in the case where the coping which forms a principal part of the parapet portion is formed of an integral extruded member, when the temperature of the coping is raised or lowered by heat transfer to or from the external atmosphere, due to the fact that there is no portion adapted to absorb thermal expansion and contraction, calkings applied at the opposite end portions of the coping between the curtain wall itself and the coping and between the building body and the coping would be broken. In the case where the coping is divided into a plurality of parts and the absolute value of the thermal expansion and contraction of the respective coping parts is reduced for the purpose of eliminating the above-mentioned shortcoming, there were the shortcomings that mounting of the coping would become complexed, and that since the mounting position of the coping to the top portion of the curtain wall and the mounting position of the coping to the building body are fixed, if dimensional errors of the coping should exist, the mounting of the coping would become difficult.